Automatic telephone system



Aug. 13, 1940. P sc 2,211,15

AUTOMATIC TELEPHONE SYSTEM Fjiled June 1, 1957 s Sheets-Sheet 1 I INVENTOR. RUD OLF PF'ANNSQHMIDT f ATTORNEY.

w a 35 m a; E A I m I), m H N5 mm 11 n: H H N m NE W 2.3 5 53 gm: J LIL m; I MME a mi... w w w @E 5i EP m N N mg 9 mm N m N r m W 2 Aug. 13, 1940.

R. PFANNSCHMIDT AUTOMATIC TELEPHONE SYSTEM Filed June 1, 1937 :5 Sheets-Sheet 2 Le RB UNMQ g RPI R81 II INVENT OR.

RU DOLF PFANNSCHMIDT ATTORNEY Aug. 33, 1940. R. PFANNSCHMIDT 2,211,359

I AUTOMATIC TELEPHONE SYSTEM I Fild June 1, 1937 3 ShQEtS-Shfifit 3 D1 D2 D3 D4 WM 66th 1012 rf rv1 I RY INVENTOR. RUDOLF PFANNSCHMIDT ATTORNEY.

Patented Aug. 13, 1940 x UNITED STATES PATENT, OFFICE to Siemens & Halske Aktiengesellschait,

Siemensstadt, near Berlin, Germany Application June 1, 1937, Serial No. 145,724

In France June 30, 1936 14 Claims.

The present invention relates to a circuit arrangement for automatic telephone systems and especially to such systems in which a plurality of exchanges are provided and in which registers are used for the establishment of calls. The invention aims at simplifying the registers which are provided in such systems and to make them suitable for coping with the various conditions of operation whicharise in such systems. For this purpose the registers are provided with a plurality of approaches, while switching means in the register determine the value and number of the additional impulse trains to be transmitted from the register or alternatively prevent any additional transmission of impulses in accordance with a characterizing condition arising at these approaches when a register is seized. A particularly convenient embodiment of the invention utilizes a single switch for fixing the value of the additional impulse trains and for determining whether there shall be any additional transmission oi. impulses.

A further characteristic of the invention consists in that in accordance with the seizing and characterizing of the approach to a register it is determined whether only a single impulse train or all the impulse trains are to be transmitted when a revertive impulse is sent out when the devices to be set by the register have been set in readiness. This arrangement enables the register to be used for establishing calls to exchanges operating in different fashions.

A further advantageous arrangement of the register consists in that the register can be seized by a preceding switch both by using a through testing lead and also by connection to a connecting line already seized by a preceding switch. In the first case the connection of a free outgoing line in the desired direction takes place at the preceding switch after the register has been seized.

Other devicescharacteristic of the invention which indicate the various applications to which the register may be put by suitable utilization of the approaches, may be deduced from the drawings and from the description.

Fig. 1 shows by way of an example a telephone system in which the register Reg 2 shown in detail in Fig. 2, parts i and 2, can be used with advantage. If the subscriber desires to call an exchange to which the line B5 leads the subscriber effects the setting of the group selector IGWI on the level 2. Over this level access is gained to a free second group selector IIGW2, This group selector becomes set on level 3. A

tree line in the direction B5 is thereupon found. A free register, for example, the register Reg 2, is set in readiness over the secondary switch MW4. The register is guarded on the seizure of the line 135. The seizure of the register Reg 2 5 by way of the secondary switch MW4 determines that the register shall not only transmit impulse trains sent to it by the subscriber but that an additional impulse train shall also be transmitted. The value of the additional impulse 10 train is determined by characterizing the particular approach to the register.

If the subscriber desires a connection in the direction B4, he sets the second group ,selector IIGW2 on level 2. This connects him to a free 16.

line in the direction B4 to which a tree register is connected by way of the secondary switch M-W5. On account of the special wiring between the secondary switch MW5 and the approach to the register, the register is caused not to trans- 20 mit impulses but merely to re-transmit those sent in to the register by the subscriber. In this case, of course, translation; of the individual impulse trains may take place.

If the group selector IIGW2 is set on the fourth 25 level the group selector tests over a secondary switch MW3 which has been set previously on a free register (for example, Reg 2). A free call finder AS is then started up and connects the line A with the line seized by the group selector. 30

mission of a corresponding number of impulses. 40

It is possible when transmitting two additional impulse trains for the value of the first impulse train to be transmitted to be in accordance with the setting of the group selector IGWI and for the value of the second impulse train to be trans- 45 mitted to be determined by the setting of the group selector IIGW2.

If the group selector IGWI is set on levels 3 or 4 the register .Reg i is connected up over this group selector and a line of the group of lines A 50 is connected over a free call finder AS. Thus calls in the trafiic direction A can be set up either by the aid of the register Reg l or by the aid of the register Reg 2.

Fig. 2, parts 1 and 2, shows the details of the The value of these impulse trains can 35 register indicated by the reference Reg 2 in Fig. 1. Two secondary switches are represented indicated MW31and MW4. These secondary switches have access to the register Reg 2 and are set in preparation on such a free register. The group selector IIGW2 shown in Fig. 2, part 1, has, as is indicated in Fig. 1, access to a number of different traflic directions. The traflic direction A is reached by setting the group selector IIGWZ on the fourth level. On setting the group selector on the level 3 access is gained to the tramc direction B5 as represented in Fig. 1. Secondary switches are associated with theoutgoing lines from a level of a group selector and these seize the same approaches to the register. It is, however, also possible to connect the secondary switch which is connected to the last contact in a level of a group selector to the register in such a way as to obtain a different mode of operation of the register in this case. This may be necessary, for example, when traversing engaged groups of lines in that in this case a special additional impulse train may be transmitted.

When the group selector is set on level 3 a secondary switch is connected to the register, the wiper so of which secondary switch is connected to the approach L0 and the wiper sb being connected to the approach Lb3. This characterization of the approaches means that the register is to receive and to transmit three of the impulse trains transmitted by the calling station and that in addition a further impulse train is to be transmitted whose value is determined by the approach (Lb-3) characterized.

If the group selector IIGW2 is set on another level, for example on the level 2, one of the traffic directions B, for example Ed in Fig. 1, is connected up. The secondary switches MWB connected to the lines in level 2 of the group selector are connected to the approach Lc by way of the contacts associated with wiper so of the secondary switch, and by way of the contacts associated with Wiper sb are connected to the approach LbO. This reference indicates that the register is only to transmit the three impulse trains sent in from the calling station without any additional impulse having to be transmitted.

If the group selector IIGW2 is set on level I the register is connected up over the secondary switch MW3 whose wiper mwc has access to the approach Lcl of the register. Wiper mwb of the secondary switch MW3 is connected to the approach L125. This characterizing of the approaches causes the register to transmit 5 impulse trains. Thus in addition to the three impulse trains transmitted by the call station two additional impulse trains are transmitted. The first of these impulse trains corresponds to the complementary number of the number 2 with respect to the number 11. The second digit which corresponds to the setting of the group selector IIGWZ is determined by the characterizing of the approach Lb5. The transmission of the additional impulse trains is effected by the aid of the switch DI. The value of these digits is computed by means of wiper ldl. If, for this sort of characterization another approach, for example the approach Lb'l, is characterized instead of the approach Lb5, the value of the second impulse train to be transmitted is adjusted in accordance with this approach.

A further specialty of the register shown consists in that in accordance with its seizure the register is in the position either to bring about the transmission of all the impulse trains when a I WC also energize.

"ready signal is received from succeeding devices or alternatively to be able to receive a ready signal before the transmission of each individual impulse train. For determining this mode of operation the lead Lel and wiper se of the seizing secondary switch are used.

A further property of the register consists in that when the group selector is set on level 3 the register is connected to line VLB which the group selector has tested as free while on the setting of the group selector IIGWZ on level 4 the group selector can test directly on a free register.

In the following description the establishment of a call by setting the group selector IIGWZ on level 3 will first be described. The register is in this case taken into use over the secondary switch MWl. The secondary switch MWI is already set in preparation on a free register. This preliminary setting of the switch MW! takes place as follows:

When the wipers of the secondary switch MW! are standing on the approaches to an engaged register the following circuit is set up: earth, contacts I 01- and 5t, rotary magnet D, battery and earth. The rotary magnet energizes and advances the wipers sa, sal, sb, so, ad, and se of the secondary switch. 1 Contact lid of the rotary battery and earth. In 'this circuit relay T remains energized over its winding II. The energizing circuit for the rotary magnet D then remains open at contact 51.. Contact St is closed and prepares a circuit over which the register, which has been connected up in preparation, when taken into use is guarded against further seizure. Contact It is closed so that the line LC is characterized as being able to be seized by the wiper awe of a hunting group selector IIGWZ.

When the group selector IIGW2 has been set on level 3 and after hunting in this level finds the line VLB to be the first free line the following circuit is set up: earth, switching means which are not shown associated with wiper awe of the group selector, lead Le, relay C, contacts 4t and l2b, lead Lcl, relay WC in the repeater Ue2,

-switching means which are not shown, battery and earth. In this circuit in addition to the testing means in the group selector, relays C and Relay WC operates its contacts 23wc whereupon relay MW and the battery connected to this relay is connected to lead Lc2. This connection of battery can be used to set subsequent switching devices in readiness, whereupon relay MW then energizes and operates contact 56 MW. The application of battery to the lead Lc2 can also serve to cause succeeding devices to connect battery to the lead Ldl so that contact 2412a is closed by the energizing of relay BA and applies earth to lead Lel. This application of earth to lead Lei is used for influencing the register in a particular way as will be described later.

When on the seizure of the lead Lc, relay C energizes contacts lc, 2c, and a.- are switched over. Contact Ic shunts contact 41.. Contact 2c sets up the following circuit: earth, contacts Mb and 2c, winding I of relay R, contact 6t, windings II and I of relay P, wiper so, contact Lo 01 the intermediate distributor ZV, winding I of relay RC, contact 51 ru, relay RZ, contact Barf, battery and earth. Relays RP, RC, and RZ operate in this circuit. Contact 8c prepares a circuit for winding II of relay R. Relay P switches over contacts Hip and I13) and closes contacts I517, 2Ip and 2217. The energizing of relay R opens contact Br and closes contact 91'. Contact I0r is open so that the deenergizing of relay T and the closing of contact 5t do not result in the energization of the rotary magnet D. Contact I Ir sets up a locking circuit for winding II of relay R. In the register relays RZ and RC are energized. Contact 3012 is opened by relay RZ thereby definitely preventing relay RU from energizing over another secondary switch. Contact 3 Irc is open so that relay T of the secondary switch MW4 releases. The contacts of relay T are thereby restored to normal which fact does not, however, influence the secondary switch MW I. Other secondary switches which were likewise set on the register which was taken into use are switched on when their T relays release through the closing of contacts corresponding to contact 5t. Contact 32rc is closed but does not promote any further switching operations. Contact 33m prepares a locking circuit for winding II of relay RB. In addition it effects the energizing of relay RR in the following circuit: earth, contacts 331's and 39m, winding I of relay RR, battery and earth. Contact 34m is opened, but this does not produce any switching operation. Contact 351a connects resistance Wi5 in parallel with winding II of relay RY in preparation. The register is now seized in the normal way and guarded so that impulses out-' going from the calling station and transmitted over the lead La as earth impulses can be received by relay A. Transmission of impulses by the register only occurs when a ready signal is sent from the repeater UeZ over the lead Lel and wiper se to winding I of relay RB. Should two secondary switches which are preliminarily set on the same register be taken into use at exactly the same time so that the relay C energizes simultaneously in two connecting lines VLB, that subscriber whose P relay was energized formerly obtains access to the free register. If this should be the relay P of the other secondary switch and the corresponding winding I of relay R does not receive suflicient current through the closing of contact I5p to energize, the corresponding secondary switch is then advanced in that the relay T of this secondary switch deenergizes when the lead Ld is broken at contact 3Irc. Another free register is then set in readiness under the control of relay T and, since the relay C of the connecting line in question has energized, is immediately guarded. If the subscriber should transmit impulses before a free register has been connected, which is imwhich has been prepared for use is prevented in this case since the opened contact Mb prevents the guarding circuit from becoming effective. when the calling subscriber replaces his receiver the seized connecting line is also released through the opening of lead Lc.

When, after the register has been seized and uarded, relay RB energizes through the closing of contacts 2417a in the repeater Ue2, the contacts of this relay (RB) are operated. Contact 2511) is opened. Contact 2611) sets up the following circuit for winding I of relay RI: earth, battery, winding I of relay RI, contacts 501p, 26rb, 33m, and earth. Contact 2Irb establishes a locking circuit for winding II of relay RE which runs from earth over contacts 331e, 69rh and NT!) to winding II of relay RB. Contacts 28rb and 29rb establish the following circuit for winding I of relay RY: earth, contact 29rb, contact kdI of the rotary magnet DI, wiper 3dl of switch DI in position 0, contacts 2811;, Sim, 6217:, winding I of relay RY, battery and earth. Relays RI and RY energize. The rotary magnet DI is connected up in the following circuit over contact 3611 on the energizing of relay RI, earth,

contacts 521p, 64ml, 38m, 3611, rotary magnet.

DI, battery and earth.- The magnet DI is operated and actuates its contact kdI. It advances the wipers IdI, 2dI, MI and ldl a step further. Relay RR is heldoperated over contacts 65ml and 49m on "the opening of the contact 39m. Contact wry energizes relay RVI over contact 661k. Relay RV is a slow relay and remains energized during the impulsive operation of contact 40w. Contact 48rvl disconnects relay RH. Contact Ii'irvl is opened. Contact 46ml breaks the circuit for relay Z which in special circumstances cooperates with the time switch at as will be described later. When contact kdl is opened after the switch DI has taken its first step, relay RY releases. Contact 381'11 brings about the deenergizing of the magnet DI. Hereupon contact kdi is again closed. Relay RY energizes again over winding I in a circuit over: earth, contact 291b, contact kdI, wiper MI in position I, contact 62m, winding I of relay RY, battery and earth. Relay RI does not release during the stepping of wiper IdI. When relay RY energizes again the rotary magnet DI isenergized once more over contact 381:1]. Relay RY is denergized again on the opening of contact kdi, whereupon the magnet DI is again deenergized. This play between the magnet DI and relay RY continues until wiper ldi rests on contact 3 which is especially characterized over wiper sb. The following circuit is set up for winding I of relay RP: earth, winding of relay RP, contacts 88m, 89ml, wiper IdI, contact 3 in the bank associated with wiper ddl, lead Lb3, a contact in the contact bank associated with wiper sb of the switch MW I, wiper sb, contact 2 Ip, winding I of relay B, battery and earth. In this circuit only relay RP energized over its winding I and operates its contacts. Contact 491p breaks the energizing circuit of relay RR so that relay RR now follows the intermittent operation of contact 39ry. Contact 501p is opened but relay RI remains energized over wiper IdI. Contact Film is closed in preparation. Contact 52m is switched over so that the further advancing of switch DI is now independent of contact 38w but is dependent upon the operation of contact 4211'. Contact 53m keeps relay RP up over winding II by short-circuiting resistance Wi9 which had previously prevented relay RP from energizing over winding II. When relay RY operates after the third step has been taken by switch DI, relay RR is caused to; deenergize. Accordingly the first impulse is transmitted over contact 431'1' and the switch Dl is stepping on to position 4 over contact 4217'. This impulse passes from earth over contacts sum, 43m, wiper sal oi the secondary switch MW4, contacts [1p and 56MW, the control relay St, battery and earth. The relay St energizes and thus transmits the impulse sent out from the register in any known manner. When contact kdl opens relay RY falls back. Contact 3911/ is closed and thereupon relay RR energizes. Magnet DI is deenergized through the opening of contact 211 and the opening of contact "rr terminates the transmission or the first impulse to be sent out. Contact kdl is closed and relay RY energizes again whereupon relay RR releases on the energizing of magnet Di and a second impulse is sent out over contact 4311'. When magnet DI energizes, contact kdl again deenergizes relay RY. During the impulse operation of winding I of relay RY winding II of relay HR is switched on by contact liry. This latter winding is disposed in parallel with the adjustable resistance WiB. By adjusting the resistance WiG the damping of relay RR can be controlled. A similar kind of damping takes place in the case of winding II of relay RY which is controlled by contact 45rr.

' Through this damping of the relays RY and RR,

the speed of operation of the switch and the length of the impulses and impulse pauses during the transmission of impulses can be adjusted to the requirements of the system.

, When the switch DI advances to position II in the manner just described, relay RY (winding ,1) is deenergized for a prolonged period since contact II at wiper 302i is not directly connected to winding I of relay 'RY. Relay RVi releases on account of contact 4011 remaining open for a long time. On the release of contact 681ml relay RH is energized. The energizing circuit for RH runs: earth,- battery, windings II and I of relay RH, contact 48ml, contact iiassociated with wiper 3dl, contact MI and 29rb and earth. Relay RH operates its contacts and locks up at contact 54m. At contact sum earth is disconnected from the pulsing circuit. Contact 621% causes relay RY to be energized afresh, whereupon the latter brings about the release of relay RR (winding I). Magnet Di accordingly receives an impulse so that the wipers oi! the switch Di are advanced to the position 0. Relay RVI does not energize on the last step of the switch since contact 681']; is open. The damping of winding II 01 relay RY is removed at contact B'Irh. The transmission of an impulse when the switch DI is stepped from position II to position 0 does not take place in spite of the closing of contact 43rr since contact sum, is opened. Contact 59m has been opened and has broken the locking circuit for winding II of relay RB. The contact 29rbis shunted by contact 60171. Relay RH makes a delayed release when the switch DI is restored to normal. Relay RP is maintained energized over its Winding II. The transmission of the digits registered in the switches D2, D3 and D4 takes place after the transmission of the digit counted up by the switch DI only if a fresh ready signal in the form of an impulse has been transmitted over contact 2417a to winding I or relay RB. The reception of incoming impulses can take place during the period of transmission by the switch Di. The incoming impulses influence relay A which is disposed in the approach La. Relay A on energizing operates contacts em, 92a, and 93a. The switch D2 which receives the first incoming impulse train is operated over the following circuit: earth contact flrq of relay RQ, which was energized over contact 33m when relay RC energized, contacts 93a, 8511, r3, "r2, rotary magnet D2, battery and earth. The magnet D2 energizes and steps on the wipers of the switch D2 one step. After relay A has released the magnet D2 is deenergized by the opening of contact 93a. During the incoming impulse trains relay RV is energized in that it is connected to earth intermittently over contact 82a. Relay RV operates its contacts and contact 98w prevents relay Z from being energized by the time switching device ZT. Contact 59112 prevents the control relay R2 from being energized over wiper ld2 during the incoming impulses. When the switch D2 has been set by an incoming impulse train, for example, by the transmission of the digit 6, the slow acting relay RV deenergizes on the prolonged release oi. relay A. The following circuit is then set up for winding I of the control relay R2: earth, battery, winding I of relay R2, wiper H12, in position 8, contacts MOI-2, Sin, 9911;, 331-0, and earth. Relay R2 operates its contacts and at contact 8'Ir2 connects the impulse circuit controlled by contact 930 to the rotary magnet D3. The magnet D2 is connected to the circuit for advancing the switch D2 at contact llllr2 and this stepping circuit becomes effective when impulses are to be transmitted from the register. Contact I00r2 'is open but relay R2 does not release since contact l02r2 has established a locking circuit for this relay. The switch D2 is first set in' motion on the re-' lease :of relay RR and the consequent closing 4 of contact 421'). The release of relay RR is dependent upon the opening of contact 2911 i. e., upon the energizing of relay RY. This relay however can only be energized if contact |93r3 is closed. This only takes place on the energizing of relay R3, that is, after an incoming impulse train has been received by the switch D3. when the calling subscriber sends out an impulse train for setting the switch D3 relay A is again impulsively energized. The rotary magnet D3 is influenced over contact 93a and steps its wipers. During the reception of these impulses relay RV is held energized over contact 92a. Contact 99m prevents relay R3 from energizing during the impulsing. If the subscriber dials the digit 7 the wipers of the switch D3 are advanced to position I. When the transmission of this impulse train is finished relay RV releases. The following circuit is then set up for winding I of relay R3:

earth, contacts 33rc, 99m, 9ia,,l 041'3, contact 7 in the contact bank of switch Id-3, winding I of relay R3, battery and earth. Relay R3 operates its contacts and locks up over contact l05r3. The switch D3 is connected in preparation to the stepping circuit for the purpose of sending out impulses at contact I06r3. Contact 961'3 connects the switch D4 to the circuit controlled by contact 930.. Contact H1313 is closed so that relay RY (winding I) can be energized for the purpose of initiating the transmission of the digit register in the switch D2, in the event of a revertive impulse having been received, in the meantime, over the lead Lel which indicates the readiness of the succeeding devices. When such a revertive impulse is received relay RB is energized over winding I. Relay RB operates its contacts and locks up over its winding II at contact 2111). This locking circuit runs from earth over contacts 33rc, 59m and 2'lrb, to winding II of relay RB. Relay RB by closing contact 29rb causes relay RY (winding'I) to energize in the following circuit: earth, battery, winding I of relay RY, contact 6217:, contact 6 in the bank associated with wiper 3d2, wiper 3d2, oil normal contact kd! of the magnet D2, contact ing wiper Sdl, contacts kdl and 29rb andearth. When relay RY energizes relay RR releases since contact 39111 is open. Through the release of contact 42rr the rotary magnet D2 is subjected to currents over earth, contacts 52m, 42m 3811, Blrp, liliri, rotary magnet D2, battery and earth. On

releasing relay RR also closes contact 45rr and by connecting up resistance W15 in parallel exerts a damping efl'ect on winding H of relay RY. In a similar way contact 4lr1 damps winding 11 of relay RR. When the rotary magnet D2 energizes wipers H12, 2112, and M2 are switched I on from position 6 to position I. The oil-normal contact lcd! is open when magnet D2 energizes. Relay RY then releases. Relay RR energizes again thereby deenergizing the magnet D2. Through the release and subsequent reenergizing of relay RR contact 4311' is transitorily closed so that animpulse is transmitted over wiper sal and the line Lal/La2. When magnet D2 releases relay RY is energized again through the closing of contact lcdi. Relay RR then releases again thereby advancing the magnet DZ one step. During this advancement relay RVI which is subjected to intermittent current over contact 4011/ is energized. The stepping of the switch D2 takes place in the manner described until the wipers reach position I l Five impulses are then transmitted. When the switch D2 reaches position ll relay RY (winding I) is deenergized for a. prolonged period since its energizing circuit is broken at wiper 3112 in position ii. Relay RVi then releases whereupon relay RH becomes energized through the closing of contact 48ml. This circuit passes from earth and battery over winding II and I of relay RH and contact 48ml and contact i i of wiper 3di, wiper Sdl, contacts lcd2 and l08r3, wiper 312i, contacts kdi, EQrb and earth. Relay RH locks up at contact iifirh and also at contact 80171. shunts contact 29rb. Relay RB (winding II) releases as soon as contact 59m opens. Contact Silrh is also open so that the release 01. relay RR when the switch D2 is advanced from position I! to position ii and the closing of contact 43rr does not cause an impulse to be transmitted. When contact 62171. is switched over relay RY (winding I) energizes over the same circuit over which winding II of relay RH is held energized. Relay RR is deenergized whereupon magnet D2 receives an impulse over contact 42rr. The damping oi winding II of relay RY is removed by the opening of contact tlrh. Through the opening of contact kd! relay RY releases again and relay RR energizes again. When the switch passes into position 8 relay R2 is deenergized. The switch D3 is accordingly connected to the stepping circuit at contact IOlr3. Relay RH is released. The stepping o1 switch D3 for the purpose of transmitting the digit which it has registered only takes place after relay RQ has released and has closed contact liih'q so as to energize relay RY. The release of relay RQis however dependent upon the opening of contact 6314 and this does not occur until relay R4 has been energized after the reception of an impulse train by the switch D4. Furthermore the transmission only takes place after relay RB has been energized over winding I on the reception of a ready impulse over the lead Lel.

The settingoi switch D4 by incoming impulses takes place in the same way as the setting of the switch D3, by the operation of contact'93a.

The circuit controlled by this contact passes through earth over contacts 94m, 93a, 95r4and 96r3 to magnet D4. During the operation of the switch D4 relay RV is energized over contact 9211. It the switch D4 is set by 8 impulses then at the end of this impulse train it will occupy the position 8. When then relay RV releases the following circuit is set up for energizing relay R4 over winding 1: earth, battery, winding I of relay R4, wiper H14, in position '8. contacts l08r4, Sia, 99m, and 331a, and earth. Relay R4 energizes and locks up at contact i09r4. Aticontact l|r4 it connects the switch D4 in preparation to the stepping circuit for the purpose of transmitting impulses. The opening of contact 95r4 prevents any further influencing of the switch by the impulse contact 93a. Relay RQ is deenergized by the opening of contact 63r4. Consequently the contacts of relay RQ are restored to normal so that if meanwhile relay RB .has been energized over winding I and has locked up at contact Zlrb the following circuitiaset up over winding I of relay RY: earth, battery, winding I of relay RY, contact 62rh, contact I in the bank associated with wiper 3113, wiper 3d3, contacts M3, iillrq, wiper 3d2;"contacts IcdZ and l03r3, wiper 3di, contacts 'kdl, 28rb and earth. At contact 3917 relayRY breaks the circuit of relay RR. This releases and causes the magnet D3 to be switched on over earth, contacts 52m and Mrnrsistance Wm, contacts 361i, I lzrq, Hi irZ, iBG'ril, rotary magnet D3, battery and earth. Ari impulse is simultaneously transmitted over contaot $317. Relay RYis deenergized by the opening of contact lcd3 and relay RR is once more energized. Relay RVi is held energized during the impulsive operation of relay RY. The stepping of the switch to position it takes place in the manner already described in connection with the other switches. When it reaches position ii four impulses have been transmitted. Relay RY is deenergized for a prolonged period and after the release of relay RVI relay RH is energized over position II of wiper M3 on the closing of contact 481ml. Relay RH by opening contact 59rh brings about the release of relay RB. Atcontact sum it prevents animpulse from being transmitted when the switch D3 is advanced from position it into position It. Relay RY (winding I) is again energized over contact 62m and relay RR releases whereupon the switch D3 passes on from position I l to position 0. Relays RH and RY release. Relay RR energizes again. In position 0 the circuit for winding I. of relay R3 is broken over wiper id3. Relay R3 releases so that the switch D4 is switched on over contact l06r3. Switch D4 is only started up when the ready impulse is sent back over contact 24ba to indicate that the device set by the transmission of the last four impulses has set free succeeding devices in readiness. When this has taken place relay RB energizes over winding I. Relay RB locks up over its winding II and contact 211*?) and on closing contact 29rbthis circuit passes from earth and battery over winding I of relay RY, contact 621k, contact 8 in the bank associated with wiper 3:14, wiper 3e74, contact kd4, wiper 3113, contacts kd3 and Tim, wiper 3d2, contacts M2 and Iilrq, wiper 3d I, contacts kdl and 29rb and earth. Relay RY deenergizes relay RR whereupon relay RR causes the magnet D4 to be switched on over contacts 42rr in the following circuit: earth, contacts 52m, 421-1, 3611, llzrq, umz, l06r3, 01-4, magnet D4, battery and earth. The magnet D4 is advanced into position It in the same way as has been described in connection with switches D2 and D3. Three impulses are accordingly transmitted over contact 43rr and the lead Lal When switch D4 advances its wipers into position ll relay RY is deenergized for a prolonged period. Relay RVI releases. The following circuit is set up: earth, battery, winding I of relay RF, position ll of wiper 3114, contact R114 and from here over wipers 3:23, M2 and Sdl to earth at contact 29rb. Relay RF energizes and operates its contacts. Contact 581'! breaks the circuit for relays RZ, RC, P and R. Relay P is the first of these relays to release and then only do the slow relays R2 and RC deenergize. Relay R remains energized over its winding II. At contact H417 relay RY (winding II) is energized in the following circuit: earth, contacts H417, "mi and 61171., winding II. of relay RY, resistance Wi4, battery and earth. Relay RY brings about the release of relay RR whereby an impulse is sent to the magnet D4 over contact 4217' and brings wipers of the switch D4 into position 0. For this position relay RF (winding 1) also releases. No further impulse is transmitted over contact W on the release of relay RR since relay P in the secondary switch MW4 has already released and has switched over contact I112. The connection over the connecting line VLB is now switched through and after relays RC and RZ have deenergized the register is released. After relay RC has released relays which are still energized in the register deenergize so that the register is now at the disposal of other calls. Should the release periods of the slow relays RVI and RC not be properly adjusted for any reason and relay RC releases too quickly the switch D4 is not advancedfrom position II to position 0 in the manner just described but when relay RY (winding II) energizes, a circuit is completed over earth, contacts 521p. 64ml, 38w, 36dl, il2rq, IOU-2, i06r3, and. M4, magnet D4, battery and earth. Relay R4 in this case is maintained energized over wiper 2614 and the normal contact 33rc until wiper M4 is set in the position 0.

As already described on each operation of the register switches relay Z is disconnected from the earth potential E either by contact 9811; or contact 46ml. Relay Z serves as a supervisory relay in the register and is caused to operate if the register does not execute any switching operation within a certain time. The connection of battery to relay Z takes place at definite intervals and in stages, the connection being eflected by the time switching device Zt as soon as the register has been seized by the energizing of relay RC. If relay Z is operated because one of the contacts 98m: and 46ml have not been operated within a prolonged interval of time after the seizure of the register, contacts zl to .28 are closed.

This results in relay B energizing over winding I. Relay B then connects its winding II to the lead Lc over contact i3b. Through the closing of contacts 19b and 20b the busy signal "Bes is. connected to the speaking leads whereby. an indithe rest position so that the following circuit is established for advancing the switches of the regnot take place for any reason.

ister into the rest position: earth, contact 33m, winding II of relay RF, wiper Zdi or 2:12 or M3 or 2114 of the first of the switches DI to D4 which is not in the rest position (for example wiper 2d! of switch D2) winding II of relay R2, battery and earth. Relay RF operates its contacts and at contact 561', guards the releasing register. The initiation of the stepping of switch D2 into the rest position is effected over earth, contacts 3410, kdi, 3d! and Him-Relay RQ has released through the opening of contacts 33rc-kd2, 3d2, 62rh, winding I of relay RY, battery'and earth. Relay RY then causes the switch D2 to he stepped into position I! over contact 38111 in the manner already described. While the switch D2 is being stepped to position ll relay RVI is operated over contact 40w. In position II relay RH is operated over wiper 3112. Over contact 62171. relay RH connects winding I of relay RY to contact H of wiper 3d2 whereupon the magnet D2 is ad- I vanced into the position 0. Relay II remains energized over the segment associated with wiper 2d2 until wiper 2112 leaves position ii. In position 0 relay R2 (winding II) also releases so that after relays RY and RF have deenergized the register remains in its normal condition.

The release of the register takes place in a similar manner if a number of its switches have been set and the complete setting of the register can- The register switches are then released in succession under the control of wipers Zdl to M4. This mode of release takes place in the case of faults in the switches themselves or in the case of negligent dialling on the part of the calling station or if the revertive impulse over the lead Lel does not materialize. The energizing of relay Z which initiates the release is only a transitory energization for after relay RC releases contact Ilirc is opened.

If the register is taken into use over a secondary switch whose wiper sb is connected to the approach Lbil, no additional impulse train is transmitted. The switching operations only differ as regards the switch Di. As regards switches D2 to D4 the switching operations correspond to those already described. If on the establishment of such a connection the register is taken into use by a switch similar to the secondary switch MW4, relays RC and RZ energize when relay C in the connecting line VLB energizes. Relay RC energizes relay RQ and winding I of relay RR by closing contact 3310. Relay RZ opens contact In the manner already described contact 3H0 effects the advancement of the secondary switches set on the same register which are not taken into use. On the closing of contact 2Ip relay RP (winding I) is energized over position 0 of wiper 4dl and over wiper sb and the approach Lbil. Relay RP is thereby held energized over winding II on the closing of contact 53m. Contact 521p is switched over thereby preparing the stepping circuit for the register switches. Contact 6|1'p is opened so that when relay RB energizes and indicates the ready condition of the devices reached over the connecting line VLB, winding I of relay RY cannot energize. The energizing of relay RI is prevented by the opening of contact 50rp. The opening of contact 4917) brings relay RR under the influence of contact 391 When relay RB energizes on account of the closing of contact 24ba and indicates the ready condition of the succeeding devices, an energizing circuit is prepared for winding I of relay RY over contact 29rb. This circuit is however only eiIective when incoming impulses have reached the 75 register; relay RB continues to hold up over contact IIrb. The incoming impulses are repeated to the register by the operation of relay A, over contact 93a. The first impulse train transmitted by the calling station passes over earth, contacts 94m, 93a, 9514, 961*3 and 9111, to the rotary magnet D2. During the reception of these impulses relay RV is energized over contact 92a. When the first impulse train has been transmitted to the register relay RV re1eases,whereupon relay R2 energizes in the manner described above.

- 3. Relay R2 then causes the rotary magnet D3 to be "connected up over contact 911-2. When the second impulse train transmitted from the calling station has been received by magnet D3, relay R3 energizes after relay RV has released over earth-,- contacts 33m, 9911;, Sid, "U3 and M3, relay R3 and battery. Relay R3 then closes contact ill3r3 whereupon the digit registered in the switch D2 is transmitted on account of the energizing of winding I of relay RY-.:'- The ener gizing circuit for the switch'D2 passes from earth over contacts 2911;, kdl and wiper 3d I in-position 0, contacts M31 3 and M12; wiper M2 in the position to which-"it has been set, contact 62172, winding I of relay Y, battery and earth. The manner in which the register operates is then the same as has already been described in con-.

nection with the establishment of the connection already discussed. The only ditl'erence resides in the disconnection of the switch DI by the immediate energizing of relay RP which in the case of the connection first described only takes place after the switch DI has counted out one digit.

The establishment of a call in which two additional impulse-trains are transmitted by switch DI from the register will now be described. Moreover in contradistinction to the embodiment already described only a single ready" signal will be assumed that it is connected to the approach N75. The wipers mwai and mum are connected to the same contacts of the register to which the wipers sat and sa can be connected. Wiper mwd of the secondary switch MW3 is connected to the same contacts of the register to which wiper sd of the secondary switch MW4 can also be connected. A wiper corresponding to wiper se is not required in the case of the switch MW3. The switch MW3 is likewise adapted to be given apreliminary setting. When the wipers of the switch MW3 are set on a busy register the magnet DMW is energized in the following circuit: earth, contacts Sci. and MI, rotary magnet DMW, battery and earth. The rotary magnet energizes and advances the wipers and energizes winding II and the relay Tl over contact dmw.

Contact it! is consequently opened and the rotary magnet is again deenergized. This stepping continues until a free register is reached. When this has occurred, winding I of relay TI is held energized over wiper mwd so that contact 2tlalso remains open and the rotary magnet DMW can no longer energize. The following circuit is set up for winding I of relay Tl: earth, contact Bel, winding I of relay TI, wiper mwd. contact LD, contact Ld, contacts 55111 and 31m, battery and earth. Relay T! has closed contact ltl. When new the group selector IIGW2 is raised to the level 4 and by means of its test wiper gwc finds that the lead L03 is the first free lead, the following circuit. is established: earth, testing device in the group selector IIGW2 which is not shownywiper gwc, lead L03, contact 28bl, relay Pl, contact itl, wiper mwc, lead Lcl, winding II of relay RC, contact 3012, relay RU, contact 58m, battery and earth. In thiscircuit the relays RU, RC, PI and the testing device in the group selector IIGWZ energize. Contact lllpi holds winding II of relay Tl energized. Contact 9pl connects winding I of relay Bi to wiper mwb in preparation. Contacts 3pl and i3pl are oper-, ated. Through the switching over of contact 3p| the lead La3 is connected to relay A of the register over wiper mwa. Relay An is energized over contact l2pl and starts up a free call known manner whereupon the testing relay PA in the call finder energizes. Relay Ci (winding II) is now also energized and switches over contact Bcl. Relay AN releases provided that no other starting impulses are received. Contacts 40!, Sci, and 6cl are opened. At contact 'Icl, winding I of relay C is connected to lead Lc3. When the call finder AS has been set relay BW in the repeater Uel energizes. Relay BW operates contact I lobw, thereby connecting relay BWI to lead L04. succeeding devices are ready to receive impulses. It operates contact Iibwl thereby connecting battery potential to lead Lad over relay JW. This connection of battery serves to energize relay RB! (winding I) in the register. Relay JW does Relay BWI energizes as soon as the.

not energize in series with winding I of relay RBI. Relays RC and RU in the register are energized. Relay RU operates its contacts and by opening contact 51111. has disconnected winding I of relay RC so that false connections caused through the energizing of relay RZ over any other secondary switch are prevented. Contact 8cm was switched over and thereby relay RPI which is connected to battery is connected to wiper ddl.

' Contact Hiiru connects earth to contact 2 of wiper Adi. Contact ll'lru connects earth over contact 2,5rb to winding I of relay RBI. Through the energizing of relay RC battery was disconnected at contact 3lrc so that the T-relays of other secondary switches which were set on the register which has been taken into use have been deenergized and have initiated the advancing of the rotary magnets and their associated switches. These rotary magnets are operated until free reg-. isters are set in readiness through the energizing of the windings I of the corresponding T relays. The secondary switch MW3 which has been taken into use is not stepped forward in spite of the opening of contact 3lrc, since a locking circuit has been set up for winding II of relay Ti over contact iOpi.

The energizing of relay RC in the register causes this register to be set in readiness in the manner which has already been described apropos of the preceding example, the energizing of relays RQ and RR (winding I) taking place through the switching over of contact 33m.

Impulse trains sent out by the calling sub scriber pass in to the register over the lead La3, contact 3pl, wiper mm and the approach La to the register of relay A. The impulses of the first impulse train are repeated to the rotary magnet D2 of switch D2 by contact 93a. While the first impulse train is being transmitted to the register relay RV is energized over contact 920. When this releases at the end of the first impulse train the control relay R2 of the switch D2 is energized by the releasing of contact 9911:. Through the energizing of the control relay R2 the rotary magnet D3 of switch D3 is connected over contact 911'! so that the next incoming impulse train is transmitted to the switch D3 over contact 93a. At the end of this impulse train relay R3 is energized when relay RV releases. This locks up over its own contact and at contact 961'3 connects the switch D4 at contact 930. for the purpose of receiving the last impulse train sent out by the calling station. After this has been received relay R4 energizes.

The register can commence to send out impulses while incoming impulses are still being received. The switch DI is set in operation on the energizing of winding I of relay RBI in that this causes relay RB to energize. The energizing of relay RB takes place when contact I23rbI is closed. In this circuit winding II of relay RBI and winding I of relay RB are maintained energized until the register is released. At contact 25rb relay RB disconnects earth at contact II'Iru from the lead LaI and by closing contact 26rb causes the control relay RI to be energized over its winding I in thefollowing circuit: earth, contacts 33rc and 28rb and 50m, winding I of the control relay RI and battery. Relay RI operates its contacts and at contact 3611 prepares a stepping circuit for the magnet DI. This circuit is established when relay RY energizes. The energizing circuit for relay RY passes from earth over contacts 29rb and kdI, wiper 3dl in position 0, contacts 281b, Sirp and 62rh, winding I- of relay RY, battery and earth. By closing contact 38w relay RY energizes the magnet DI over earth contacts 52m, 64rpI, 38m, and 36M and magnet DI. Relay RY (winding I) is deenergized by the opening of contact Full. Contact 38ry is opened, whereupon magnet DI releases. During this stepping of the switch DI, relay RVI is impulsively operated over contact 40m and thus remains operated during the stepping on account of its slow to release feature.

When wiper 4dI of the switch DI passes into position 2, the following circuit is set up: earth, contacts IISru, and I2Irx, contact 2 in the back associated with wiper fldI, wiper ldI, contacts 89ml, 88m, I22r:c, winding I of relay RPI, battery and earth. In this circuit relay RPI energizes. A locking circuit is established for this relay over its winding 2 through the closing of contact IIIIrpI and in this circuit relay RX also energizes. The approach Lb! is connected to contact 2 associated with wiper ldI at contact I2Ira: so that during the second operation of the switch DI which will be described laterthis approach can also be assessed if it should be characterized. Contact I 221's prepares for the connection of relay RP to wiper IdI. Contact 89ml is open. Relay RX also prepares a locking circuit for itself over contact 9m. Through the switching over of contact 6419i and 65ml the switch DI is controlled after relay RPI has energized in dependence upon relay RR so that the steps which the switch DI takes after relay RPI has energized cause impulses to be sent out over the lead 10!. This generation of impulses continues to take place until the switch DI reached position II so that when it has reached position I I, nine impulses have been transmitted. This impulse transmission takes place in the same manner as was described in connection with the first embodiment in that relay RY (winding I) controls winding I of relay RR, this being effected by the aid of contact 391g after contact 65ml has opened. When the switch DI reaches position II relay RH energizes over contact 48ml afterv relay RVI has released, the circuit being earth, contact 29rb, off-normal contact kdI, wiper Sdl, contact lI associated with wiper 3dI, contact 58ml, windings I and II of relay RH and battery. Relay RH operates its contacts and by opening contact 9Ilrh prevents a further impulse from being transmitted over the line and the approach Dal when the switch DI advances from position II to position I]. Through the switching over of contact 621% winding I of relay RY is connected to contact II associated with wiper BdI whereupon this relay energizes. Relay RPI is deenergized through contact 59rh opening because its locking circuit is then broken. Relay RB does not release since its winding I remains connected in series with winding II of relay RBI. Relay RX holds up over winding I. After contact 64ml has released the switch DI is advanced to position I) when contact 38m closes. While the switch DI is taking this step relay RR is energized because contact 65ml was closed. This prevents a further impulse from being transmitted over the lead Lal when relay RH releases when the switch DI reaches position 0. Relay RI does not release when the switch DI reaches position I] since contacts 26rb and 50717 are closed.

A further advancing of the switch DI for the purpose of transmitting a second impulse train is now again dependent upon winding I of relay RY which operates the magnet DI over its contact 3811/. The transmission of impulses in accordance with the particular approach LbI to Lb8 which has been characterized takes place with the aid of relay RP (winding I) which now is connected to wiper 4dI over contacts I22r:r, 88m, and BQTpI. The first energization of relay RY for advancing the switch DI from position to position I takes place over earth, contacts 2911) and lcdl, wiper 3dI, contacts 28rb, Birp, and 62m, winding I of relay RY and battery. The magnet DI operates and opens the oil-normal contact lcdI, whereupon relay RY releases again. Relay RR (winding I) remains operated for the closed contacts 65ml and 49m. The stepping of the wipers of switch DI in the manner described in connection with the first embodiment continues until wiper fldI reaches that approach of the approaches LbI to Lb8 which has been characterized. If for example lead Lb has been characterized in that this contact has been connected to a contact associated with wiper 'mwb of the secondary switch MW3 on the seizure of the register the following circuit is established when wiper MI is set on contact 5: earth, winding I of relay RP, contacts I22ra3, 88m and 89rpi, wiper Adi in position 5, contact L125, wiper mwb, contact Spi, winding I, relay BI, battery and earth. In this circuit winding I of relay RP energizes. Winding I of relay BI does not receive sufflcient current so this relay does not energize. Through the operation of relay RP winding I of relay RR is made dependent upon the operation of contact 39m by the opening of contact 49m. The magnet DI is controlled in the manner already described by the aid of contact 42rr since on the operation of relay RP contact 521;) has also been switched over. Impulses are now transmitted over the lead Lal by contact 4317'. When wiper 31 passes into position I I, relay RH is energized. Relay RI-I by opening contact Sllrh prevents an impulse being transmitted when the switch Dl is set in the normal position. Relay RP remains energized over contact 3310 after contact 5317) has closed until the register is released. When the switch DI passes into position 0 relay RI releases since its circuit is broken at wiper ldl and contact Slim is held open. 'Relay' RY now energizes over winding I since it can be assumed that the switches D2 and D3 have been set meanwhile by the calling station. Relay Y is energized over earth contact 29rb, oil normal contact kdl, wiper 3dl, contact E0313, of the energized control relay R3 of the switch D3, contact me, wiper 3:22 in any position, contact 621%, winding I of relay RY, battery and earth. Relay RY then causes relay RR (winding I) to release by opening contact 39111! whereupon the switch D2 can receive impulses over contacts 52m, 42, 3611, Sirp and lilir2. The transmission of the impulse trains registered in the switches D2, D3 and D4 then sets in in the normal way as already described in connection with the first embodiment. When the last switch D4 is advanced into position i i winding I of relay RF energizes. The opening of contact 581' then brings about the deenergization of relays RU and RC in the register and of relay Ri in the secondary switch MW3. The deenergizing of relays RC and RU in the register cause the energized relays IBP, RX, RB and RBl in the register to release. Through the closing of contact ll lrf relay RY receives current over its winding II. Magnet Dd energized over earth contacts 52m, litrpl, 38ry,-. 36rl, li2rq, liHrZ,

W613, and Hurt whereupon. switch Dt also advances to position 6. Relay Rd which was held energized over earth, contact 331'0, IIRF, Zdl, 2122, 2113, 2(14 andR tII so thatafter the release of relay RF the register is at the disposal of other calls.

The release of relay Pl in the secondary switch MWQ does not cause the secondary switch MWE to be advanced since relay Cl is held operated over its winding I and lead L03 during the time that the call is in progress over the line BL and so the contact 5cl remains open. Only relay T5 in the secondary switch MW3 releases on account of the circuit for its winding II being opened at contact iilpi. If for any reason the register should now have been set within the prescribed time for time switching device Zt becomes operative so that relay Z is energized. Hereupon contacts Zl to Z8 are closed. Earth is hereby connected to the seized approach of the register. In the case of seizure over the secondary switch MW3 energization of winding I of relay Bl is brought about. Relay Bl operates its contacts and over contact 3011i and 3lbl connects the busy signal Best to the speaking leads thereby intimating to the calling subscriber that he should replace his receiver. Contact 2822i connects winding II of Bi to lead L03 over which relay Bl holds upon until the release of the conenergized. The release of therelay Pi causesrrelay PA in the call finder to deenergize thereby initiating the release of the call finder. The release of relay RC in the register permits the release of the register in the manner already deergizes over the released contact 33m. In this event the relay RY which controls the stopping of the register device receives current over its winding II through contact H41? and by energizing the corresponding rotary magnets advances the wipers of the corresponding switches into the appropriate position whereuponthe register releases in the normal way.

What is claimed is: 1. In anautomatic telephone system, a register sender provided with a plurality of ap-' proaches, means in the register for receiving and retransmitting impulse trains and for transmitting additional impulses, means for seizing the register over one of the approaches and transmit ting impulses thereto, an impulse controller in the register operating in accordance with the approach over which the register was seized for controlling the number of additional trains of impulses transmitted by the register or alternatively preventing any additional transmission of impulses.

2. In a transmission system, a plurality of lines, a register sender accessible over a. plurality of paths, means in the sender for receiving and retransmitting series of impulses and for transmitting additional impulses, means'controlled from any line for seizing the sender over any of said paths and for transmitting impulses thereto, said sender operated to transmit additional impulses dependent on the path over which it is seized and to then retransmit the received impulses.

3. An automatic circuit arrangement as claimed in claim 1, in which the impulse controller comprises switching means having a single bank of contacts.

4. An automatic circuit arrangement as claimed in claim 1, in which all functions of the impulse controller are effected in a single switch through one and the same wiper. I i

5. An automatic circuit arrangement as claimed in claim 1,- in which operation of the impulse controller is controlled by means of difierent potentials depending upon the approach over which the register was seized.

6. In an automatic circuit arrangement, a register sender having a plurality of approaches, means for seizing the register sender over any one of the approaches and for transmitting trains of impulses thereto, means in the register sender for receiving said trains of impulses, means in the register sender for transmitting trains of impulses dependent upon the received trains of impulses and for transmitting additional impulses, said last means including a stepping switch having a normal position and a relay for controlling said switch, said relay having an auxiliary winding for damping the action thereof and at times for controlling the return of said switch to normal, and an impulse controller in the register sender for controlling in accordance with the approach over which the register sender was seized the number of trains of additional impulses transmitted, or alternatively, for preventing transmission of any trains of additional impulses.

7. A transmission system as claimed in claim 2, including switching means in the sender operated when the sender is seized over a particular path for determining the value of a train of said additional impulses.

8. In an automatic circuit arrangement, a plurality of register senders each having a plurality of approaches, a plurality of lines each having means associated therewith for seizing a register over one of the approaches and transmitting impulse trains thereto, means in the register for receiving and registering said impulse trains and other means in the register for transmitting additional impulse trains, means for retransmitting registered impulse trains, and means responsive to seizure of the register over a particular approach thereof for rendering said other means inoperative and causing said transirntting means to become operative,

9. In an automatic telephone system, lines of different classes, control equipment, means for seizing said equipment over any one of said lines for the extension of a call and for transmitting thereinto trains of impulses comprising call directing digits, means in said equipment for registering said digits and for transmitting trains of impulses dependent upon the registered digits, and means in said equipment for determining the class of said one line and, in dependence upon its class, for transmitting one or more trains of impulses in addition to those trains of impulses transmitted'in dependence upon said registered digits.

10. In a telephone system, a first exchange trunk lines of different classes outgoing from said exchange, means for seizing any one of the lines for a call to a distant exchange, controlling equipment in said first exchange common to said lines, means for associating said equipment with the seized trunk line responsive to the seizure thereof and marking said equipment according to the class of the seized line, an impulse generator in said equipment, and means in said equipment rendered efiective by an impulse reverted thereto over the seized line from the distant exchange for determining from said marking the class of the seized line and for controlling said generator to transmit over said line a train of impulses dependent in number upon the class of said line,

11. In a telephone system, trunk lines divided into groups which are further divided into subgroups, means for seizing any one of said trunk lines, controlling equipment common to said lines, a plurality of paths over which said equipment may be seized, means responsive to the seizure of said one trunk line for seizing, said equipment over a particular path depending upon the group of which the seized line is one and marking said equipment according to the sub-group of which the seized line is one, and an impulse generator in said equipment controlled both by the path over which the equipment was seized and by the marking of said equipment to transmit impulses over said one trunk line, the path of seizure determining the number of trains of impulses, if any are to be transmitted, and the marking determining the number of impulses, if any, in one of the trains.

12. In a signalling system, a register, means for controlling said register to store a plurality of digits, a line, an impulse sender controlled by said register and at times responsive to the receipt of an impulse over said line to transmit over said line a plurality of trains of impulses dependent upon the stored digits, said sender at other times responsive to the receipt of an impulse over said line to transmit only one of said trains of impulses.

13. In a signalling system, a register, means for controlling said register to store a plurality of digits, 9. line, an impulse sender controlled by said register for transmitting in succession over said line a plurality of trains of impulses depending upon the stored digits, means in said sender required to be operated to initiate the transmission of each of said trains of impulses, said last means operated over said line to initiate the transmission of a train of impulses and normally restored after the initiation of the transmission of that train of impulses, thereby requiring its reoperation over said line to initiate transmission of each train of impulses, and means effective at times for holding said last means operated after its initial operation thereby causing all of said trains of impulses to be transmitted responsive to a single operation of said last means.

14. In control equipment accessible to lines of difierent classes, discriminating means operated by the seizure of the equipment over one 01 said lines and determining the class of the seizing line, registering means controlled over the line an outgoing line, means controlled by said registering means for transmitting in succession a plurality of trains of impulses over said outgoing line, and means operated over said outgoing line before said impulses are transmitted thereover, said last means at times operated but once to permit all of said trains of impulses to be transmitted and at other times operated once to permit each train of impulses to be transmitted, depending upon the class of the seizing line as determined by said discriminating means.

RUDOLF PFANNSCHLHD'I. 

